Internal-combustion engine



FIG. 1 is a perspective view of internal-combustion engine, showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a top plan view of thereof;

FIG. 5 is a bottom plan view thereof

FIG. 6 is a right side elevation view thereof; and,

FIG. 7 is a left side elevation view thereof. 

The ornamental design for, internal-combustion engine, as shown and described. 